Well drill and casing drive unit

ABSTRACT

A drive unit attaches to the mast of a drilling rig and operates to simultaneously drill the well and insert a casing. Drill pipe segments are rotated by a spindle extending down from a rotary drive section which contains a hydraulic motor and transmission. A power chuck surrounds the spindle and operates to grasp and hold the upper end of the casing segment that surrounds the drill. The power chuck is resiliently mounted underneath the rotary drive section and includes a vibrator which when actuated aids insertion of the casing.

United States Patent [191 Perlewitz [1 1 3,734,212 1 May 22,1973

1541 WELL DRILL AND CASING DRIVE UNIT [7 5] Inventor:

Ralph L. Perlewitz, Milwaukee, Wis.

Bucyrus-Erie Company, South Milwaukee, Wis.

Aug. 20, 1971 Assignee:

Filed:

App]. No.:

References Cited UNITED STATES PATENTS 3/1970 Kato ..173/49 X Ink, m. '1'

7 l 50 i i Brown ..175/l7l X 2/1971 Ishii Primary Examiner-Emest R. Purser Attomey-Barry E. Sammons et a1.

[57] ABSTRACT A drive unit attaches to the mast of a drilling rig and operates to simultaneously drill the well and insert a casing. Drill pipe segments are rotated by a spindle extending down from a rotary drive section which contains a hydraulic motor and transmission. A power chuck surrounds the spindle and operates to grasp and hold the upper end of the casing segment that surrounds the drill. The power chuck is resiliently mounted underneath the rotary drive section and includes a vibrator which when actuated aids insertion of the casing.

5 Claims, 9 Drawing Figures PATENTEBXAYZZ U75 SHEET 1 [1F 4 INVENTOR RALPH E. PERLEWITZ ATTORNEY PATENTEUHH'ZZiSB sum 2 OF 4 INVENTOR RALPH E. PERLEWITZ ATTORNFY PATENIED M22 1975 SHEET 3 BF 4 "mm Mum-E K MW ATTORNEY PATENTEU HAYZZ I975 SHEET l UF 4 R O T N E V N RALPH E. PERLEWITZ ATTORNEY WELL DRILL AND CASING DRIVE UNIT BACKGROUND OF THE INVENTION The field of the invention is drilling machines used to drill water, gas and oil wells, in formations of the type requiring the insertion of a casing to prevent the sides of the well from collapsing and, or prevent the entrance of contaminants into the well.

In present rotary drilling operations it is standard practice to first drill the hole and then insert the casing. Drill pipe segments are successively raised, attached to the preceding drill segment and driven downward by a rotary drive unit. When drilling deep wells, the weight of the drill stem itself provides the necessary downward driving force on the drill bit, however, when drilling shallower wells, such as water wells, a downward force is applied to the drill stem by the rotary drive unit. When drilling is completed, the drill string is removed from the well and easing segments are successively welded together and driven downward into the well.

This drilling method is both time consuming and costly. To drill the well, individual drill segments are hoisted up to the vertical drill mast by means of block and tackle arrangements. They are then-either used immediately, or stored with several other drill segments for subsequent use. In either case, drilling is repeatedly stopped while drill segments are raised to the vertical and attached to the drive unit and the drill stem. When the desired depth is reached, the procedure is reversed by withdrawing and detaching drill segments. Repeated delays are again encountered as drill segments are lowered from the mast back to their storage position. After the drill stem is completely removed, casing segments are hoisted to the vertical, as was done in the drilling operation, and then inserted into the well. As in the drilling phase of the operation, delays occur each time it is necessary to hoist a casing segment from its storage position to the mast.

SUMMARY OF THE INVENTION The present invention provides a drill and casing drive unit for use in the drilling method described in the co-pending application Ser. No. 173,523 entitled Well Drilling Method wherein the casing is inserted while the hole is being drilled. The drive unit comprising the present invention includes a rotary drive section adapted to connect to and rotate the upper end of the drill pipe, and a power chuck section connected to the rotary drive section and operable to grasp the upper end of a surrounding casing and drive it downward during drilling. The required feed force on both the drill and casing is accomplished by slidably mounting the drive unit to the mast and feeding it downward at an appropriate rate.

It is a general object of the invention to provide a drive unit which will receive a drill segment and surrounding casing segment and drive them downward together. The rotary drive section includes a spindle which attaches to the upper end of the drill segment and the chuck section is operable to grasp the upper end of the casing segment and hold it tightly during insertion into the well.

Another object of the invention is to improve insertion of the casing by vibrating it during drilling. To accomplish this, the power chuck section is resiliently connected to the rotary drive section and the chuck section is vibrated during drilling. The resilient connection isolates the vibrations to the chuck section and casing.

The foregoing and other objects and advantages of the invention will appear from the following description. In the description reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration and not of limitation a preferred embodiment of the invention. Such embodiment does not represent the full scope of the invention, but rather the invention may be employed in many different embodiments, and reference is made to the claims herein for interpreting the breadth of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in elevation of a drilling rig incorporating the present invention,

FIG. 2 is a view in elevation of the mast of the drilling rig of FIG. 1,

FIG. 3 is a view in cross section of the mast of FIG. 2 taken on the plane 33,

FIG. 4 is a partial view with parts cut away of the drill segment and easing segment connected to the drive unit,

FIG. 5 is a front view with parts cut away of the invented drive unit,

FIG. 6 is a top view of the drive unit,

FIG. 7 is a bottom view of the drive unit,

FIG. 8 is a view in cross section with parts cut away of the rotary drive portion of the drive unit in FIG. 6 taken on the plane 8-8, and

FIG. 9 is a view in cross section of the power chuck portion of a drive unit in FIG. 7 taken on the plane 99.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a drive unit 1 is shown perched atop a mast 2. The mast 2 is part of a drilling rig described more fully in the co-pending application Ser. No. 173,519 entitled Mobile Drilling Unit. The mast 2 is pivotally attached to the front of a truck 3, and is driven by a pair of hydraulic cylinders 4 between an upright drilling position and a horizontal traveling position (shown in phantom in FIG. 1).

Located on the truck 3 is a storage rack 5 containing three tiers of drill and casing segments. When ready for use, each drill segment is inserted in a casing segment with a portion of the drill segment exposed out the back or top end of the casing segment. A transfer arm 6, also pivotally connected to the front of the truck 3, is driven by a third hydraulic cylinder 7 from a horizontal pick position adjacent the storage rack 5 to an upright ready position adjacent the mast 2. Upper and lower mandibles 8 and 9 on the transfer arm 6 grasp segments of drill and casing from the storage rack 5 and lift them to a vertical ready station adjacent the mast 2. The upper mandible 8 grasps the exposed end of the drill segment and the lower mandible 9 grasps the casing segment at the opposite end. The transfer arm 6 rotates on command to swing the drill and easing segments from the ready station to a drilling position directly over the well and under the drive unit 1. For a detailed description of the structure and operation of the storage rack 5 and transfer arm 6, see the co-pending application Ser. No. 173,197 entitled Well Drill Transfer Mechanism.

Referring to FIGS. 2 and 3, the mast 2 includes two tubular stanchions and 11 connected together in spaced parallel relationship. Extending along the length of the stanchions 10 and 11 are tracks 12 and 13. Each track 12 and 13 is rigidly attached to its respective stanchion 10 and 11 by a plurality of spaced brackets 14.

The tracks 12 and 13 run parallel to one another and have a channel-shaped cross section with the open side of each facing the other. The drive unit 1 is equipped with four wheels 15 that fit snugly in the channelshaped tracks 12 and 13. The drive unit 1 is propelled along the tracks 12 and 13 by a standard hydraulic cylinder actuated rope and pulley hoist and feed assembly attached to the back side of the mast 2. This feed assembly is standard and other systems such as rack and pinion or worm gear feed assemblies can be substituted.

Referring to FIGS. 2 and 5, the drive unit 1 includes a rotary drive section 16, and a chuck section 17 suspended beneath it. The top pair of drive unit wheels 15 are securely attached to the rotary drive section 16 by means of upper side frames 18 bolted to the sides of the drive section 16, and the lower pair are attached to lower side frames 19, also bolted to the sides of the rotary drive section 16, but extending downward below the chuck section 17. A rotary spindle 20 extends downward from the underside of the rotary drive section 16, completely through the chuck section 17, and terminating in a tapered threaded portion 21. As shown in FIG. 4, this threaded portion 21 of the spindle 20 is adapted to screw into the upper end of a standard drill pipe segment 22.

To isolate the chuck section 17 which is vibrated during the drilling operation, it is resiliently connected to the underside of the rotary drive section 16. Referring to FIGS. 5 and 9, a circular ring plate 23 is fastened by bolts 24 to the underside of the rotary drive section 16, around and concentric to the spindle 20. Securely fastened to the ring plate 23 by bolts 25 are a plurality of J-shaped support brackets 26. The support brackets 26 are spaced about the circumference of the ring plate 23, and extend downward and inward towards the spindle 20. The inward turned portion of each bracket 26 forms a shelf upon which a lower stack 27 of elastomeric material such as natural or synthetic rubber is placed. Placed on the top surfaces of the lower stacks 27 is a rigid floating ring plate 28. It is aligned concentric to the spindle 20 directly beneath the ring plate 23. Sandwiched between the top surface of this floating ring plate 28 and the bottom surface of the ring plate 23 are a plurality of upper stacks 29. The upper stacks 29 are also made of an elastomeric material and are equally spaced about the circumference of the rings 23 and 28.

With this arrangement, the floating ring plate 28 is resiliently retained between the upper and lower stacks 29 and 27, concentric with the spindle 20, and directly beneath the drive section 16. The chuck section 17 is rigidly fastened to the underside of the floating ring plate 28 by a plurality of bolts 30 which are inserted upward through flanges 31 formed around the top of'the chuck section 17. Each bolt 30 passes through a post 32 and screws into the underside of the floating ring plate 28. The posts 32 space the top surface of the flanges 31 well below the support brackets 26 to provide clearance between them when the chuck section 17 is vibrated.

The primary function of the rotary drive section 16 is to rotate the spindle 20. Referring to FIG. 8, the rotary drive section 16 is basically comprised of a housing 33 containing a gear train which mechanically links the spindle 20 to a hydraulic motor 34 mounted on the top surface of the rotary drive section 16. The spindle 20 extends upward through the housing 33 and is rotatably secured to it by means of a lower thrust bearing 35 mounted in a circular cavity on the underside of the housing 33, and an upper thrust bearing 36 mounted in a circular cavity in the top of the housing 33. Axial movement of the spindle 20 is prevented by the combined lower thrust bearing 35 acting downward against the top surface of a flange 37 formed on the spindle 20, and the upper thrust bearing 36 acting upward against the lower edge of a retainer cap 38. The retainer cap 38 is screwed onto a threaded top portion of the spindle 20 after the spindle 20 is inserted into the housing 33 during assembly. The cavity containing the lower thrust bearing 35 is covered with an annular-shaped protective cover 39 bolted to the underside of the housing 33. The cover 39 forms a seal with the spindle 20 to prevent foreign substances from entering the lower cavity and retain lubricant in the lower thrust bearing 35. Likewise, the upper thrust bearing 36 is protected by means of an annular-shaped cap 40 bolted to the top surface of a housing 33. The cap 40 extends radially inward into sealing engagement with the retainer cap 38, and upward to form the sidewalls of a chamber to be described in further detail below.

A pinion gear 42 mounted in the housing 33 has a shaft which extends upward to connect to the hydraulic motor 34. The pinion gear 42 is rotatably attached to the upper and lower walls of the housing 33 by bearings 43. Rotary power is transmitted from the pinion gear 42 to an idler gear 44 also rotatably attached to the top and bottom walls of the housing 33 by means of bearings 45. The idler gear 44 has a large lower segment 46 which engages the pinion gear 42, and a smaller upper segment 47 which engages a bullgear 41 formed around the spindle 20. The difference in size of the lower and upper segments 46 and 47 provides a speed reduction between the hydraulic motor 34 and the spindle 20 which it drives.

The chuck section 17 of the drive unit 1 is generally cylindrical in shape with an opening running through its center from top to bottom through which the spindle 20 passes. Referring to FIGS. 7 and 9, the lower end of the central opening is enlarged and beveled to allow easy insertion of a casing segment 48. Three stop bars 49 located in the chuck section 17 are spaced around the circumference of the central opening, and protrude radially into it. The casing segment 48 is inserted up into the chuck section 17 until the upper edge of the casing 48 makes contact with the stop bars 49.

Spaced circumferentially between, and axially below the stop bars 49 are three chuck jaws 50, each retained in a slideway formed in the walls of the chuck section 17. When moved radially inward, serrated faces of the chuck jaws 50 engage the exterior of the casing 48. Located in cavities directly above the chuck jaws 50 are three cams 51. The earns 51 are slidably retained within these cavities by a collar 52 fastened to the top surface of the stop bars 49. The lower section of each cam 51 is angulated and received into an angulated opening through the chuck jaw 50 associated with it. A downward sliding motion of the cams 51 inserts their angulated sections further into the associated chuck openings, causing the chuck jaws 50 to slide radially inward toward the casing 48. Conversely an upward movement of the cams 51 withdraws the chuck jaws 50 away from the casing 48.

The cams 51 are actuated by three double-acting pistons 53 located in cylindrical cavities 54 formed in the walls of the chuck section 17 directly above each cam 51. The pistons 53 translate vertically in their cylinders 54 and a set screw 55 is inserted through a hole in the side of each cam 51 and fastens the lower end of each piston 53 to the top of its associated cam 51. The top end of each piston 53 is enlarged to form a head 56 which is in sealing engagement with the walls of its cylindrical chamber 54. Fluid ports (not shown) connect the cylindrical chambers 54 to a hydraulic control system, which system is operable to move the pistons 53 up or down to actuate the chuck jaws 50.

A vibrator unit 57 is fastened to the back side of the chuck section 17 by bolts 58. There are numerous types of vibrators available which will operate satisfactorily to drive the easing into the well, the most desirable type, however, is that which is adjustable in both frequency and amplitude. The vibrations aid in driving the casing 48 into the drilled well, and therefore, flexibility in the choice of frequency and amplitude is desirable to maintain maximum drilling rates in all types of soils.

When drilling, it is desirable to provide bailing air to clean the well. This is accomplished by directing pressurized air downward through the hollow spindle and drill segments 22. Referring to FIG. 8, pressurized air is received in a hose 59, the end of which is securely attached to a top plate 60. The plate 60 is in turn fastened to the top edge of the cap 40 by bolts 61 to form an airtight chamber around the upper opening in the spindle 20. Air passes down the spindle 20 and drill stem to the drill bit, and returns up the annular space between the drill and casing. The returning air with entrained cuttings passes up through the chuck section 17 where it is diverted out to the side of the drive unit 1 by a canopy 62 attached to the top of the chuck section 17 around the spindle 20. The air and cuttings are diverted into a flexible conduit (not shown) attached to the mast and discharged at ground level.

OPERATION The transfer arm 6 holds the drill segment 22 and surrounding casing segment 48 directly underneath the spindle 20. The drive unit 1 is lowered and the spindle 20 is rotated to screw its threaded end into the drill segment 22. The upper mandible 8 on the transfer arm 6 is then released and swung clear, and the drive unit 1 is lowered further to envelop the upper end of the casing segment 48. Pressurizing the top chambers of the cylinders 54 forces the pistons 53 and cams 51 downward. The camming action causes the chuck jaws 50 to slide radially inward into engagement with the casing segment 48. The lower mandible 9 is then released and the transfer arm 6 returned to its horizontal position.

After attachment to the drill and casing segment, the drive unit 1 is again lowered and the spindle 20 is rotated to screw the lower end of the drill segment 22 into the top end of the drill string in the well. Following this attachment, the drive unit 1 is lowered further to butt the lower end of the casing segment 48 against the upper end of the casing already inserted in the well.

The casing segments are welded together and drilling is recommenced.

Drilling is accomplished by rotating the spindle 20 and exerting a downward feed force on the drive unit 1. The downward feed force is applied to the drill seg ment 22 by the spindle 20, and to the top edge of the casing segment 48 by the stop bars 49 in the chuck section 17. This feed force is supplemented by vibrations transmitted from the vibrator 57 to the casing 48.

The drive unit 1 advances down the tracks 12 and 13 until it reaches the base of the mast 2. At this point drilling is stopped and hydraulic fluid is pumped into the lower chambers of the cylinders 54 causing the pistons 53 and cams 51 to translate upward releasing the casing segment 48 from the grip of the chuck jaws 50. The drive unit is then raised to lift the top end of the drill string above the upper edge of the casing 48. The exposed drill string is grasped by a wrenching mechanism (not shown) located at the base of the mast 2 and the spindle 20 is rotated in reverse direction unscrewing itself from the drill string. The drive unit 1 is raised to the top of the mast 2 where the cycle is repeated.

The entire drilling operation can be carried out by a single operator in the truck. Drill and casing segments are lifted to the mast while the drilling is being performed. The drive unit is easily and rapidly detached from the preceding drill and casing segments. It is driven back up the mast where the next drill-casing segment is swung underneath it for rapid attachment. The simultaneous drilling and insertion of the casing contemplated by this invention, along with the rapid interchange capability of the drive unit, provides a considerable savings in time which substantially reduces the cost of drilling the well.

I claim:

1. In a drilling rig having an upright mast and means for transferring drill and casing segments to a drilling position, the improvement comprising a drive unit slidably mounted to said upright mast and operable to bore a hole in the earth and insert a surrounding casing in the same operation, said drive unit comprising:

a rotary drive section operable to connect with and rotate a drill segment located in said drilling position; and

a power chuck section resiliently connected to the rotary drive section and including chuck means which is operable to grasp and hold a casing segment surrounding a drill segment located in said drilling position, and a vibrator unit which is operable to vibrate said chuck section during said drilling operation.

2. The drive unit as recited in claim 1 in which the power chuck section includes a floating ring plate, the rotary drive section includes a support bracket, and said resilient connection between said rotary drive section and said power chuck section is made by clamping the floating ring plate between the support bracket and the rotary drive section with an elastomeric material disposed on each side of the floating ring plate.

3. The drive unit as recited in claim 2 in which said power chuck section is positioned beneath said rotary drive section and said spindle extends downward from said rotary drive section and through a central opening in said powerchuck section, wherein said floating ring plate is concentric about said spindle and there are a plurality of support brackets which extend downward 4. In a drilling rig having an upright mast and means i for simultaneously transferring drill and easing segments to a drilling position, the improvement comprising a drive unit slidably mounted to said upright drill mast and being operable to connect with both a drill and casing segment held in said drilling position and to simultaneously rotate said drill and drive said casing segment downward, said drive unit comprising:

a rotary drive section which includes a rotatably v mounted spindle that extends downward therefrom and is driven by a motor to rotate about a central axis; and a power chuck section connected beneath said rotary drive section and disposed around a portion of said spindle, said power chuck section including a plurality of slidably mounted jaws with associated drive means, which jaws are radially operable with respect to said central axis, wherein a drill segment in said drilling position is connectable to the lower end of said spindle and the casing segment associated with said connected drill segment is connectable to said power chuck section by the operation of said jaws and in which said power chuck section includes stop means against which the upper end of the connected casing bears.

5. The drive unit as recited in claim 4 wherein said spindle extends downward, completely through said power chuck section. 

1. In a drilling rig having an upright mast and means for transferring drill and casing segments to a drilling position, thE improvement comprising a drive unit slidably mounted to said upright mast and operable to bore a hole in the earth and insert a surrounding casing in the same operation, said drive unit comprising: a rotary drive section operable to connect with and rotate a drill segment located in said drilling position; and a power chuck section resiliently connected to the rotary drive section and including chuck means which is operable to grasp and hold a casing segment surrounding a drill segment located in said drilling position, and a vibrator unit which is operable to vibrate said chuck section during said drilling operation.
 2. The drive unit as recited in claim 1 in which the power chuck section includes a floating ring plate, the rotary drive section includes a support bracket, and said resilient connection between said rotary drive section and said power chuck section is made by clamping the floating ring plate between the support bracket and the rotary drive section with an elastomeric material disposed on each side of the floating ring plate.
 3. The drive unit as recited in claim 2 in which said power chuck section is positioned beneath said rotary drive section and said spindle extends downward from said rotary drive section and through a central opening in said power chuck section, wherein said floating ring plate is concentric about said spindle and there are a plurality of support brackets which extend downward from said rotary drive section to form a shelf upon which said floating ring plate is clamped.
 4. In a drilling rig having an upright mast and means for simultaneously transferring drill and casing segments to a drilling position, the improvement comprising a drive unit slidably mounted to said upright drill mast and being operable to connect with both a drill and casing segment held in said drilling position and to simultaneously rotate said drill and drive said casing segment downward, said drive unit comprising: a rotary drive section which includes a rotatably mounted spindle that extends downward therefrom and is driven by a motor to rotate about a central axis; and a power chuck section connected beneath said rotary drive section and disposed around a portion of said spindle, said power chuck section including a plurality of slidably mounted jaws with associated drive means, which jaws are radially operable with respect to said central axis, wherein a drill segment in said drilling position is connectable to the lower end of said spindle and the casing segment associated with said connected drill segment is connectable to said power chuck section by the operation of said jaws and in which said power chuck section includes stop means against which the upper end of the connected casing bears.
 5. The drive unit as recited in claim 4 wherein said spindle extends downward, completely through said power chuck section. 